Method of blending fuels and related system

ABSTRACT

A method and related system blend fuels and dispense a blended fuel to a vehicle at a fueling station. In one aspect, the method comprises selecting the desired proportion of at least one of the fuels available at the service station, blending that fuel with another one available, and delivering the blended fuel to the vehicle. Preferably, the first fuel is a non-renewable, petroleum based one, while the second fuel is a non-petroleum based, renewable one (such as ethanol or biodiesel).

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/763,291, filed Jan. 30, 2006, the disclosure ofwhich is incorporated herein by reference.

COPYRIGHT STATEMENT

A portion of the disclosure of this document contains material subjectto copyright protection. No objection is made to the facsimilereproduction of tile patent document or this disclosure as it appears inthe Patent and Trademark Office files or records, but any and all rightsin the copyright(s) are otherwise reserved.

TECHNICAL FIELD

The present invention relates generally to a method of blending fuelsand, more particularly, to blending renewable fuels, such as biodieseland ethanol, with petroleum-based fuels, such as gasoline and diesel, ata fueling station for vehicles.

BACKGROUND OF THE INVENTION

Over the past thirty years, significant attention has been given to theproduction of ethyl alcohol, or “ethanol,” for use as an alternativefuel. Ethanol not only burns cleaner than fossil fuels, but also can beproduced using corn, a renewable resource. At present, an estimatedsixty-nine “dry milling” plants in the United States produce over threebillion gallons of ethanol per year. Additional plants presently underconstruction will add hundreds of millions of gallons in an effort tomeet the ever-increasing demand.

Besides ethanol, a great deal of attention is presently being given to anewer class of alternative fuels, loosely termed “biodiesel.” Likeethanol, biodiesel is also a clean burning fuel produced from renewableresources, such as animal fats, soybean oil, corn oil, and waste greasefrom cooking. Although biodiesel contains no petroleum, it can beblended at any level (proportion) with petroleum-based diesel to createa blended fuel. Such blended fuel can be used in existing diesel engineswith little or no modifications.

At the present time, feedstocks (i.e., corn, fats, greases, etc.) arecollected and transported to regional facilities for conversion toethanol or biodiesel. From there, the end products are transported tolarge terminals for mass blending with diesel fuel or gasoline. Theresulting mixture is then transported to fueling stations, such as viatanker truck or rail car. There, it is of course manually pumped intothe self-contained fuel tanks of vehicles through a nozzle associatedwith an individual fueling terminal or “gas pump.”

Despite the prevalence of the foregoing model for the past severaldecades, it is relatively inefficient and inflexible. Although anyconcentration of ethanol can be used as a gasoline additive, higherconcentrations require an adjustment to the engine controls, such astiming. However, the consumer presently has no choice but to use theethanol-gasoline blend as formulated for delivery to the fuelingstation.

Additionally, in October 2004, President Bush signed into law a blenderstax credit to stimulate biodiesel production. This law provides that foreach gallon of biodiesel blended with petroleum diesel, the blendershall receive a one dollar tax credit for a specific type of oil or fatconverted and 50 cents per gallon on others. While the law stimulatesinterest from the owner of the fuel terminal to use biodiesel due toprofit incentives, it does not in any way encourage the interest of thefuel station owner or the individual consumer. If the biodiesel wereinstead blended at the pump, then the fueling station would receive thetax credit directly and have the ability to pass a portion onto theconsumer.

Moreover, the ability to selectively increase the amount of biodieselused at the service station would encourage consumers to use a greaterconcentration than might otherwise be selected by the field. Assumingdiesel and biodiesel are sold for $2.50 per gallon (including federaland state taxes for each), the influence of the tax credit on particularconcentrations is shown in the following table:

B80=20%*$2.5+80%*($2.5−$1)=$1.70 per gallon

B60=40%*$2.5+60%*($2.5−$1)=$1.90 per gallon

B20=20%*$2.5+20%*($2.5−$1)=$2.30 per gallon

B5=95%*$2.5+5%*($2.5−$1)=$2.45 per gallon.

B2=98%*$2.5+2%*($2.5−$1)=$2.48 per gallon

Consequently, the owner of the fueling station would be encouraged topass a portion of the savings to the end user in order to sell morebiodiesel and obtain a higher tax credit.

U.S. Pat. No. 6,422,465 to Miller, the disclosure of which isincorporated herein by reference, discloses a process for custom mixingfuel at the point of purchase. However, the proposal is to use a barcode associated with the vehicle or its fuel tank to determine the blendto be created. A significant disadvantage thus results, since the useris unable to select the proportion of the renewable fuel, and mustinstead rely on the information contained in the bar code. There is thusno incentive to increase the amount of renewable fuel used in the blend.

Accordingly, a need is identified for a method for blending renewablefuels with petroleum based fuels in a more efficient and effectivemanner, and preferably at the “point of sale” based on a user-selectedproportion of the renewable fuel. The method would encourage the use ofsuch fuels by station owners as well as consumers, and would allow forthe particular blend to be selected “at the pump” or otherwise onsite toavoid the need for pre-delivery blending at an offsite location, such asat a regional facility, or otherwise at a fixed concentration ratio.Eliminating this step in the conventional process would significantlyreduce costs, which would be passed onto the end consumer. The methodwould be simple in operation, and could be accomplished using existingtechnology, thus potentially allowing for the implementation of arelatively low-cost retrofit solution.

SUMMARY OF THE INVENTION

In accordance with one aspect of the invention, a method of dispensing ablended fuel to a vehicle at a fueling station is disclosed. The methodcomprises, at the fueling station, selecting a proportion of a firstfuel comprising the blended fuel. The method further comprises blendingthe first fuel in the selected proportion with a second fuel, anddelivering the blended fuel to the vehicle.

Preferably, the first fuel is selected from the group consisting ofbiodiesel, ethanol, and mixtures thereof and the second fuel compriseseither diesel or gasoline. The method may further comprise the step ofpumping at least the first fuel from a storage vessel through flowcontrol valves for blending. Preferably, the selecting step comprisescontrolling a valve to adjust the flow of the first fuel from thestorage vessel.

In some situations, the method may involve substantially matching thetemperature of the first and second fuels before the blending step. Thisstep may be combined with monitoring the temperature of at least one ofthe first and second fuels during delivery. The method may furtherinclude the step of metering the flow of the first and second fuels,either by way of a flow meter or a metering pump.

In addition, the method may involve the use of a third fuel blended onsite with another fuel to create a second blended fuel. Preferably, thethird fuel is biodiesel in the case where the second fuel is ethanol. Inany case, the selecting step may be performed by the owner of thefueling station, or alternatively the consumer.

Another aspect of the invention involves a method of encouragingresource conservation at a fueling station for dispensing a blended fuelto a vehicle. The method comprises blending a renewable and anon-renewable fuel at the fueling station to produce the blended fuel.The method further comprises obtaining a tax credit from the amount ofthe renewable fuel in the blended fuel.

Preferably, the method also comprises selecting the amount of at leastone of the renewable and non-renewable fuel comprising the blended fuel.Still more preferably, the step of pricing the blended fuel according tothe tax credit obtained is also performed. To encourage use of therenewable fuel, the method may further involve displaying the amount ofsavings realized by the consumer by selecting a particular blended fuel.

Yet another aspect of the invention is a system for dispensing blendedfuel at a fueling station having a first storage vessel having a firstfuel at the fueling station and a second storage vessel having a secondfuel at the fueling station. The system comprises a fuel terminal with anozzle adjacent the storage vessels. A selector is provided forselecting a proportion of at least one of the first or second fuels tobe blended with the other to create a blended fuel for delivery throughthe nozzle. A blender blends the first fuel with the second fuel at theselected proportion to form a blended fuel delivered through the nozzle.

Preferably, the blender includes a flow control valve associated witheach storage tank and a common line for receiving the flow of each fuelfrom the corresponding storage vessel. More preferably, the blendercomprises at least one metering pump. A common delivery line may beassociated with the nozzle and the blender, and may further include amixer.

The system may further include a third storage vessel having a thirdfuel and a fourth storage vessel having a fourth fuel. In that case, asecond selector is provided for selecting a proportion of the third fuelto the fourth fuel to be blended. Blending may be by way of a secondblender for delivery through the nozzle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating one possible embodiment forpracticing the disclosed invention;

FIG. 1 a is a schematic diagram illustrating another possibleembodiment;

FIG. 2 is a block diagram showing another aspect of the invention;

FIG. 3 is a partially block, partially schematic diagram illustratingyet another aspect of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Reference is now made to FIGS. 1-3, which together illustrate anddescribe various aspects of the present invention in more detail. In itsbroadest terms, the present invention relates to a method of blending atleast one renewable fuel with a non-renewable fuel “at the pump” (i.e.,at the point of sale) and a related fueling station pump (hereinaftercalled a “terminal” to avoid confusion with onboard vehicle fuel pumpsand the pumps that may be used to deliver the fuel from a storagevessel) that meters out the desired proportion of fuels in blended form.The method thus allows for the end consumer to select and control theblend of two fuels, such as one that is renewable and one that is not,in order to conserve energy and perhaps even obtain a reward in the formof a reduction in fuel cost.

In the most preferred embodiment, the blending is of biodiesel withdiesel, or ethanol with gasoline. However, the method is not necessarilylimited to these fuels and may apply without limitation to mixing anytype of renewable fuel with a non-renewable one “at the pump” orotherwise at the service station (as contrasted with a location remotefrom the service station, such as at a refinery or an intermediateprocessing plant).

In its simplest form, the inventive method is implemented by modifyingan existing fuel dispensing terminal at a fueling station to bespecially adapted for pumping a fuel blended onsite, such aspetroleum-based diesel and biodiesel. As a result, the fuel pumpingoperation works similar to that presently done with regular diesel orgasoline, such as with the vehicle arriving at the fueling station,followed by the selection of the method of payment and taking stepsnecessary to pump the fuel (e.g., by lifting an associated handle,pressing a button, or otherwise communicating a signal to commence thepumping). However, in addition to these conventional steps, theinventive method requires the step of selecting the type of renewableand non-renewable fuels to be blended and the particular proportion orconcentration desired. This may be accomplished using any type ofsuitable selector, such as a push button, touch screen, mechanical dial,or other form of switch that allows one to choose the proportion of theat least two fuels to be blended.

In one proposed embodiment, as shown in FIGS. 1 and 1 a, the basic“blended” fuel dispensing system 10 may include a self-service terminal12, as well as an elongated hose connected to a nozzle 14 for deliveringthe fuel (but could of course comprise multiple nozzles andcorresponding hoses; see, e.g., U.S. Pat. No. 5,163,586 to Zinsmeyer,the disclosure of which is incorporated herein by reference). Besidesthese conventional structures, at least one additional fuel holdingvessel is required, such as one for biodiesel (e.g., vessel 16 b in FIG.1, with vessel 16 a holding petroleum-based diesel). Of course, in thecase of gasoline, the other vessel may hold ethanol. Likewise, vessels16 c, 16 d for both ethanol and biodiesel can be provided, along withthe conventional separate vessels for diesel fuel and gasoline, allassociated with the terminal 12 in a like manner. Regardless of theparticular set-up used, each vessel 16 a . . . 16 n generally includesor is associated with a pump 18 to supply the pressure for pumping thecorresponding fuel from the storage vessel or the like to the individualservice station terminal 12 (see FIG. 2).

With this type of basic arrangement, a selected blend of fuel can bemetered with a “blender.” In one possible embodiment, this blender maybe in the form of a simple valve operating between the vessels 16 a, 16b and the nozzle 14. As illustrated schematically in FIG. 2, this valvemay comprise a flow control valve 20 located, for example, at theindividual terminal 12, and may be associated with one or more flowmeters 22 for monitoring the output amounts (see FIG. 3). Alternatively,as shown in FIG. 1 a, a metering pump 24 may be associated with eachfuel storage vessel in order to precisely blend and control the flow ofthe fuels being combined, while obviating the need for flow meters. Ineither case, the opening and closing of the valves or the operation ofthe metering pump to achieve the selected blend may be electronically ormechanically controlled based on the selected input.

To ensure a reliable, consistent output from nozzle 14, it may bebeneficial to mix the fuel products being blended at similartemperatures. As illustrated in FIG. 3, an effective method is to use aheat exchanger 26, such as a small plate and frame heat exchanger inwhich the two fuel products slated for blending are separated by thewalls of the heat exchanger. This allows the temperatures to approacheach other prior to being mixed. Additionally, the temperature of thefuel(s) can be monitored, as represented by block 28, and adjustmentsmade, if necessary, to account for extreme weather conditions.

After the fuel products exit the metering lines (and any heat exchanger,if present), they may enter a common line 14 a associated with thenozzle 14 for delivery to the tank of the associated vehicle. In thisline, turbulent flow may be created using a mixer 30. The mixer 30 maycomprise an inline mixer with stationary paddles around the inner tubewalls (not shown). This helps to ensure that the fuel products blend ina suitable fashion before exiting the nozzle 14 and entering the vehicletank. Of course, in the case where blended fuel is delivered to thecommon line 14 a from different sets of storage vessels, it may beassociated with a control valve (not shown) adjusted based upon theselected blend.

Another aspect of the invention comprises blending the fuel at the pump,and then obtaining any tax incentive (credit) available to reduce theoverall cost of the blended fuel to the provider. The tax savingsobtained can then be used by the provider to price the blended fuelaccordingly. This directly passes the savings realized to the endconsumer and thus promotes resource conservation by encouraging theconsumer to use the blended fuel (and typically in the highest feasibleamount to obtain the maximum savings). As an adjunct of this method, thefuel station owner could also dynamically display (either at the pump oron a detached sign) the amount of savings that would be realized by theconsumer by selecting a particular blend (e.g., B80 $1.70 per gallon,B60=$1.90 per gallon, B20=$2.30 per gallon, B5=$2.45 per gallon,B2=$2.48 per gallon), thereby encouraging the use of a higher proportionof the renewable fuel.

The following is a prophetic example of one manner in which the presentinvention might be successfully practiced.

EXAMPLE

A consumer arrives at the fueling station in a vehicle in need ofrefueling. Upon pulling up adjacent to the fuel terminal, the consumersees a display associated with the terminal showing that first andsecond fuel blends are available: each comprising biodiesel and dieselin inverse proportions (80/20; 20/80). The price for the 80/20 blend is$1.70 per gallon and the price for the 20/80 blend is $2.30 per gallon.The user manually selects the 80/20 blend.

The nozzle is placed in the appropriate location for filling thevehicle. An associated switch is triggered to commence flow through thenozzle. Metering pumps simultaneously deliver a 4:1 ratio of biodieselto diesel by pumping a suitable volume of fluid per unit time fromcorresponding storage tanks to a common line in which the blended fuelis created. The consumer pays in the conventional manner depending onthe amount of fuel metered. The station owner, having already passed thesavings on to the consumer, then claims a tax credit for each gallon ofbiodiesel utilized.

The foregoing description provides illustration of the inventiveconcepts. The descriptions are not intended to be exhaustive or to limitthe disclosed invention to the precise form disclosed. Modifications orvariations are also possible in light of the above teachings. Forexample, although not the conventional process, the fuel could bemanually dispensed from the storage vessels 16 a, 16 b at the fuelingstation, blended by mixing in a single vessel, and delivered to thevehicle. Also, while providing at least two storage vessels isdisclosed, it should be appreciated that the method may further includeadditional storage vessels for other fuels capable of being blended andused in powering vehicles or the like. While the focus is also onblending biodiesel with diesel or ethanol with gasoline, the blendingtechniques and apparatus may apply to blending any renewable fuel withany petroleum base fuel, including diesel with ethanol. The embodimentsdescribed above were chosen to provide the best application to therebyenable one of ordinary skill in the art to utilize the inventions invarious embodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention.

1. A method of dispensing a blended liquid fuel to a vehicle at afueling station, comprising: at the fueling station, selecting aproportion of a first liquid fuel; selecting a proportion of a secondliquid fuel; substantially matching a temperature of the first andsecond liquid fuels before blending; blending the first liquid fuel inthe selected proportion with the second liquid fuel; and delivering theblended liquid fuel in a liquid phase to the vehicle.
 2. The method ofclaim 1, wherein the first fuel is selected from the group consisting ofbiodiesel, ethanol, and mixtures thereof and the second fuel compriseseither diesel or gasoline.
 3. The method of claim 1, further comprisingthe step of pumping at least the first fuel from a storage vesselthrough flow control valves for blending.
 4. The method of claim 1,wherein the selecting step comprises controlling a valve to adjust theflow of the first fuel from the storage vessel.
 5. The method of claim1, further including the step of monitoring the temperature of at leastone of the first and second fuels during delivery.
 6. The method ofclaim 1, further including the step of metering the flow of the firstand second fuels.
 7. The method of claim 1, further including the stepof blending a third fuel with one or more other fuels to create a secondblended fuel.
 8. The method of claim 7, wherein the first fuel isgasoline, the second fuel is ethanol, the third fuel is diesel, and theone or more other fuels is biodiesel.
 9. The method of claim 1, whereinthe selecting step is performed by the owner of the fueling station.